This is a monthly series illustrating several characteristic moths
to look out for in our area. Text and photos by Roy Leverton.

You can also view the other months by selecting the links at the bottom of this page.

Minor Shoulder-knot Brachylomia viminalis

Late July to early September.

Damp woodland and sallow carr.

Widespread but local, this little noctuid seems to have got scarcer in recent years. In the 1990s I recorded up to 16 per night at my Banffshire site, but now see just two or three per year. Yet the habitat seems unchanged.

After overwintering as an egg, the caterpillar feeds in spring in spun-together terminal leaves of sallows and willows, a habit shared with numerous other species. Occasionally the adult can be found at rest by day on sallow trunks, but is more often seen at light or sugar.

Click on the image to enlarge it.

Beech-green Carpet Colostygia olivata

Late July through August.

Woodland and moorland.

Beech-green Carpet is widespread in the Highlands (though not the Islands), but it is local, requiring basic rocks and soils. Unlike its ubiquitous relative the Green Carpet (see July 2009), it is absent from acidic areas despite the presence of its foodplants, bedstraws.

The delicate olive green pigments of freshly emerged moths are unstable, soon fading to brown. Such individuals are occasionally mistaken for Large Twin-spot Carpet, a non-Scottish species, before the error is realised.

Like many carpets, the adult is easily disturbed by day, but flies naturally from dusk onwards, often nectaring at flowers.

Click on the image to enlarge it.

Bedstraw Hawk-moth Hyles gallii

Late May to August.

Mainly near coasts.

This striking hawk-moth is a scarce migrant to our area from the Continent. As such, it can turn up anywhere, particularly near the coast. Despite its southerly origin, there are more sightings in Orkney and Shetland than anywhere else in Scotland, a testament to the moth's powerful flight.

Many arrive here in perfect condition, having migrated soon after emergence; females may be unmated. Nevertheless, on rare occasions caterpillars have been found in Scotland, either on bedstraws or on willowherb, though whether they successfully complete their life cycle in the wild is unlikely.

Newly arrived migrants visit nectar flowers to replenish their resources, sometimes in broad daylight but more often at dusk.

Click on the image to enlarge it.

Mother of Pearl Pleuroptya ruralis

Gardens, hedgerows, open woodland, waste ground.

Mainly late July to early September

This very large crambid is often mistaken for a macromoth by beginners. Its wings are thinly scaled and translucent, with an opalescent sheen when fresh, hence its common name.

Nettle is the main larval foodplant, and further south this moth is common wherever that plant grows. However, in our area it is scarcer and may be largely migratory rather than a permanent resident. Certainly it appears erratically at my Banffshire site, nor is it seen every year.

The adult flies gently when disturbed by day. At night it visits nectar flowers such as buddleia and sometimes comes to lighted windows as well as moth traps.

Click on the image to enlarge it.

Broad-bordered Yellow Underwing Noctua fimbriata

Late July into September.

Woodland, scrub, hedgerows, rural gardens.

This widespread moth is a classic low-density species, found almost everywhere but only in small numbers. The contrast with its abundant relative, Large Yellow Underwing, could hardly be greater. At my own site the best total for one night is 4 and 673 respectively, a ratio that is typical judging by the NMRS data. Yet there is no obvious reason for the huge difference in population density. Both species occupy similar habitats, have a similar life cycle and share the same foodplants.

Broad-bordered Yellow Underwing is a bulky moth with a rather geometric pattern. Unfortunately the striking orange and black hindwings are only revealed in flight, or in a set specimen. The moth itself seems relatively inactive, spending the hottest part of the summer in aestivation. At night it sometimes visits buddleia.